1. Field of the Invention
The present invention relates generally to an apparatus for determining the force produced by a tire assembly. More particularly, the present invention relates to an apparatus which determines the force produced by a tire over a stepped or uneven surface.
2. Disclosure Information
Various systems have been proposed for measuring tire contact pressure indicative of the force produced by the tire. These systems measure the tire force to aid in the testing and design of the tire tread for example. An example of one such system is disclosed in U.S. Pat. No. 4,986,118 wherein a test apparatus includes a plurality of tire contact pressure sensors mounted in a linear array across a bearing plate which the tire rolls over during the test. Strain gauges are secured to the pressure sensors and provide an electrical signal having a characteristic indicative of the measured tire force. The known system described works well when testing a tire over a flat, even road surface but no means are disclosed for testing the tire on a stepped or uneven road surface. Furthermore, when a plurality of pressure sensors are used, it is necessary to provide a microprocessor or other data collecting apparatus having a plurality of data channels for receiving the plurality of generated signals. The plurality of pressure sensors also increases the cost of the test apparatus.
It would be advantageous to provide a test apparatus which overcomes the deficiencies of the known system and is capable of testing a tire over an irregular or stepped surface without adding to the cost of the system or the complexity involved in receiving a plurality of data signals.